I've really warmed up to the Unchained Monk and I'm trying to put together a character for what will be a somewhat villainous (though not necessarily evil) campaign. The concept just screams out for the Martial Artist archetype, so I'm trying to balance the old with the new.
This is what I've come up with, but I'd appreciate any input when it comes to relative balance - am I getting over or am I screwing myself?
Martial Artist Abilities:
Pain Points
Originally came at 3rd, replacing Still Mind; now comes at 4th replacing Still Mind.
Exploit Weakness
Originally came at 4th, replacing Ki Pool (& Ki Strike); now comes at 3rd, replacing Ki Pool, Ki strike & all Ki Powers.
Martial Arts Master
Originally came at 4th, replacing Slow Fall; now comes at 4th replacing nothing.
Extreme Endurance
Originally came at 5th, replacing Purity of Body, Diamond Body & Perfect Self; now comes at 5th, replacing Purity of Body, Timeless Body & Perfect self.
Physical Resistance
Originally came at 7th, replacing Wholeness of Body, Timeless Body & Tongue of the Sun and Moon; now comes at 7th replacing nothing.
Bonus Feat
Originally came at 12th replacing Abundant Step; now does not get the bonus feat at all.
Defensive Roll
Originally came at 13th level, replacing Diamond Soul; now comes at 13th level replacing Tongue of the Sun and Moon.
Quivering Palm
Additional uses began at 15th level; now the class does not get it at all.
Greater Defensive Roll
Originally came at 19th level, replacing Empty Body; now it comes at 19th level replacing Flawless Mind.
Thoughts?
You're giving up Ki pool, 9 Ki powers (7 of which are old monk abilities retro-fitted into ki powers), and 5 other monk abilities For the stuff from martial artist. Seems to me, it's a bad trade off, but if that's the concept you wanna play, then go for it - trade off be damned.
However, If I were to do the conversion, this is what I'd do....feel free to use, dismiss, or ridicule it as you see fit.
Exploit Weakness: Replaces ki pool, ki strike, and the ki powers gained at 10th, 18th, and 20th levels. Since it replaces ki pool and unchained monk gets ki pool at 3rd level, so should martial artist.
Pain Points: same as above, the ability it replaces is now at 4th level, so that's when it should kick in.
Martial Arts Master: replaces the ki power gained at 4th level.
Extreme endurance: replaces purity of body, perfect self, and the ki power gained at 6th level.
Physical Resistance: replaces timeless body, tongue of the sun and moon, and the ki power gained at 8th level.
Bonus Feat: replaces the ki power gained at 12th level. Since you're losing so much versatility for the flavor of martial artist, I'd keep the bonus feat here.
Defensive Roll: replaces the ki power gained at 14th level.
Quivering Palm: yeah, you're just gonna have to eat the loss on this one OR use the core monk version of quivering palm that doesn't use the ki pool.
Greater Defensive Roll: replaces flawless mind and the ki power gained at 16th level.
I think most of these should replace the ki powers, and thus be gained at even levels.
Pain Points & Exploit Weakness as you've listed them.
Replacing ki powers:
4th Martial Arts Master
8th Physical Resistance (also replacing Timeless Body, and TotSaM)
10th Extreme Endurance (among with Purity of Body and Perfect Self)
12th Bonus feat
14th Defensive Roll
16th Quivering Palm (original version, with bonus uses)
18th Greater Defensive Roll
It's lacking something for 6th level, maybe High Jump (which the original archetype keeps)?
Edit: 20th level ki power is missing a replacement as well.